Parathyroid imaging

Advances in diagnostic imaging methods during the last decade have facilitated the identification of focal or diffuse parathyroid abnormalities. Major advances have included improvements in computed tomography and high-resolution ultrasonography, and the introduction of thallium-201-technetium-99m parathyroid subtraction scintigraphy. The more invasive methods of venous sampling and selective angiography have also been refined, but they have not been used as extensively because of the need for highly skilled personnel. The role of these diagnostic tools before surgery in the routine evaluation of patients with suspected primary hyperparathyroidism is unclear because a skilled surgeon should be able to achieve cures in 90% of these patients during exploratory surgery. However, most physicians would agree that, in those patients whose abnormalities go undetected during exploratory surgery of the neck, diagnostic imaging methods should be used before additional surgery is planned. Further prospective studies are needed to determine if routine localization before surgery is cost effective.     

Intraoperative Parathyroid Hormone Monitoring Corroborates the Success of Parathyroidectomy in Children

Ob­jec­ti­ve: To assess the efficacy of intraoperative parathyroid hormone (PTH) monitoring in evaluating the outcome of parathyroidectomy in pediatric patients.Methods: Intraoperative PTH monitoring during parathyroidectomy was performed in five children (3M, 2F); three had parathyroid adenomas (single gland disease) and two had primary hyperplasia. One patient had undergone two previous surgical interventions to remove the parathyroid glands, but the PTH levels had remained high with persistence of symptoms. Immunoradiometric analysis was used for PTH measurements. Preoperative PTH values were obtained to monitor the baseline levels. Serum samples were collected 20 minutes after removal of the adenoma/parathyroid gland(s) and PTH levels were compared with preoperative values. Specimens were also confirmed by frozen sectional examination. Results: Mean age of the patients was 11 years (range: 3 months-16 years). Mean preoperative PTH values were 633.3±579 pg/mL (range: 143-1300 pg/mL). Intraoperative values decreased to 18.7±5.5 pg/mL (range: 8-27 pg/mL) following removal of the gland(s). Normal calcium levels were achieved with adequate management following surgery. One patient (with multiple surgeries and found to have an ectopic parathyroid gland) had hungry bone syndrome after the operation and was treated successfully. There were no major complications. All patients maintained normal calcium/phosphorus levels in the follow-up period, ranging from 2 to 5 years.Conclusion: An ectopic parathyroid gland or another undetected adenoma can be overlooked during surgery. Owing to the short life of the hormone, intraoperative PTH monitoring to determine PTH clearance proved to be a feasible marker for adequacy and safety of surgery and “cure”.     

Parathyroidectomy: Overview of the Anatomic Basis and Surgical Strategies for Parathyroid Operations

It is imperative for the surgeon who performs parathyroidectomy to have a thorough understanding of the anatomy and embryology of the parathyroid glands in order to optimize the cure rate for patients with hyperparathyroidism (HPT). Furthermore, all clinicians caring for patients with hyperparathyroidism should be aware of the advancements in preoperative parathyroid localization, intraoperative PTH monitoring and surgical strategies for treatment of hyperparathyroidism. In this chapter, the anatomy and embryology of the parathyroid glands will be reviewed. The available surgical options for treatment of patients with hyperparathyroidism will be addressed, including “focused” parathyroidectomy, bilateral neck exploration, radioguided parathyroidectomy, and endoscopic and video-assisted parathyroidectomy. The unique challenge associated with reoperative parathyroidectomy for persistent or recurrent hyperparathyroidism will be outlined. Finally, insight into how to locate a qualified surgeon will be provided and recommendations will be made on what constitutes an appropriate choice of operation for specific patients with primary hyperparathyroidism.     

Evaluation of Parathyroidectomy for Secondary and Tertiary Hyperparathyroidism by the Parathyroid Surgeons’ Society of Japan

Secondary hyperparathyroidism (SHPT) remains a serious complication in patients with chronic kidney disease, and some patients require parathyroidectomy. The Parathyroid Surgeons’ Society of Japan (PSSJ) evaluated parathyroidectomy for SHPT and tertiary hyperparathyroidism (THPT) in Japan. The annual numbers of parathyroidectomies between 2004 and 2013 were evaluated using questionnaires. Since 2010, the PSSJ has registered the patients. In total, 826 patients from 42 institutions were registered. The annual number of parathyroidectomies for SHPT and THPT in Japan increased from 2004 to 2007 and then decreased markedly after 2007, with 296 operations performed in 2013. The number of women and men was almost equal (397/427). Median (interquartile range) age of these patients was 59.0 (24–87) years, the duration of hemodialysis before parathyroidectomy was 10.83 (0.0–38.7) years, and diabetic nephropathy was 87/826 (10.5%). Of these patients 59.6% were treated with cinacalcet at undergoing parathyroidectomy. In 75.3% of patients, a total parathyroidectomy with forearm autograft was performed. In 77.7% of patients, four or more parathyroid glands were removed during the initial operation. The incidences of husky voice and wound hemorrhage were 2.9% and 1.1%, respectively. The number of parathyroidectomies for SHPT in Japan decreased markedly after the introduction of cinacalcet. Based on the evaluation of registered patients, parathyroidectomies have been successfully performed at the institutions participating in the PSSJ.     

Parathyroid incidentaloma discovered during thyroid ultrasound imaging

We report two patients with incidentally discovered enlarged parathyroid glands while performing neck ultrasonography (US) for thyroid nodules. The parathyroid masses were seen as hypoechoic, homogeneous, oval nodules, separated from the thyroid gland. Both patients were completely asymptomatic, although subclinical evidence of hyperparathyroidism (serum PTH and calcium levels in the upper limit of the normal range, increased ionized serum calcium, osteocalcin, urinary calcium and hydroxyproline) was subsequently found in one patient. An enhanced uptake on sesta-MIBI scinti scan was concordant with the US finding in the two cases. PTH levels in the wash-out from the US-guided fine needle aspiration biopsy, confirmed the parathyroid origin of the lesions. Cytology and immunocytochemistry were, in our cases, unreliable diagnostic procedures. The extensive use of US imaging in thyroid pathology may increase the finding of US incidentally discovered parathyroid adenomas. The early detection of silent parathyroid pathologic findings may extend the natural history of these masses to a preclinical stage. Further investigations are necessary to evaluate the evolution of parathyroid incidentalomas and therefore their clinical significance.     

A Retrospective Study of the Impact of Intraoperative Intact Parathyroid Hormone Monitoring During Total Parathyroidectomy for Secondary Hyperparathyroidism: STARD Study

The study aimed to evaluate the diagnostic accuracy of intraoperative intact parathyroid hormone (IO-iPTH) in patients with secondary hyperparathyroidism (HPT).The cut-off for IO-iPTH monitoring remains unknown.This was a single-center retrospective review of 226 consecutive patients (107 males and 119 females) who underwent parathyroidectomy data for secondary HPT between May 2010 and March 2014. The predetermined cut-off for IO-iPTH was a 70% IO-iPTH drop from baseline 10 minutes after total parathyroidectomy and thymectomy. We used <60 pg/mL iPTH value on postoperative day 1 (POD1) as an indicator of successful removal of parathyroid glands and reviewed the frequency of reoperation other than in autografted sites during the observation period. This study was based on the Standards for the Reporting of Diagnositic accuracy compliant.The reoperation rate in patients with >60 pg/mL iPTH value (POD1) was significantly higher than that in patients with <60 pg/mL iPTH value (POD1), (13.0% versus 0.5% P = 0.003). Sensitivity, specificity, and accuracy of >70% IO-iPTH drop were 97.5%, 52.2%, and 92.9%, respectively, this criterion was demonstrated to be beneficial in 26 patients. In 5 patients, <70% IO-iPTH drop was observed and further exploration enabled sufficient removal of parathyroid glands. In 21 patients, although fewer than 4 parathyroid glands were removed after enough explorations, >70% IO-iPTH drop enabled termination of operations and iPTH value (POD1) was <60 pg/mL.An iPTH value of <60 pg/mL (POD1) was a good predictor for successful parathyroidectomy. A 70% IO-iPTH drop from the baseline was appropriate to determine sufficient parathyroid gland removal during parathyroidectomy for patients with secondary HPT.     

Severe Pancreatitis after Parathyroidectomy

Cope showed in 1957 that pancreatitis may be the presenting symptom in hyperparathyroidism. Since then, the literature has reported a coincidence of primary hyperparathyroidism and pancreatitis between 1% and 19%, but the true relationship has not been fully established. When severe pancreatitis follows parathyroidectomy, a condition familiar to parathyroid surgeons, reports are mostly anecdotal and by many authors considered to be coincidental. We present the case history of a 58-year-old man with a longstanding history of untreated primary hyperparathyroidism who developed severe pancreatitis immediately after removal of a 400-mg parathyroid adenoma. He was the first in a series of 108 operated patients to develop this complication. His preoperative levels of parathormone and serum calcium were the highest in our material. We believe that pancreatitis after parathyroidectomy is a real but rare complication that might be predicted by preoperative high values of serum calcium and parathormone.     

Acute Thyroiditis Complicating Parathyroidectomy

This report describes a 59-year-old man who presented 10 days after surgery for hyperparathyroidism with pulmonary edema, mildly abnormal echocardiogram, and elevated free T4 level with suppressed thyroid-stimulating hormone level. Follow-up documented resolution of the elevated free T4 level with 24-hour thyroid scan and uptake at 60 days showing reduced uptake and normal gland anatomy. Previous case reports have been made of thyroiditis at variable time intervals after parathyroidectomy and are here reviewed. This entity represents an under appreciated potential morbidity associated with parathyroid surgical procedures.     

Impending paradoxical embolus: Clinical imaging and successful surgical treatment

In a patient with pulmonary emboli, transesophageal echocardiography showed a thrombus straddling the foramen ovale (impending paradoxical embolism). Proximal pulmonary emboli were visualized by spiral computed tomography and subsequent surgical treatment, consisting of removal of intracardiac clot, closure of the open foramen ovale and pulmonary embolectomy, was successful.     

Parathyroid and autoimmunity

Data in favor of chronic hypoparathyroidism as an autoimmune disease are examined. The article takes into consideration the different clinical forms, genetic patterns, histopathology, animal models, cellular immunity, circulating autoantibodies, target autoantigens, clinical manifestations, laboratory diagnosis and therapy. Furthermore, data on 71 Italian patients with chronic hypoparathyroidism are presented.     

Parathyroidectomy for patients with renal osteodystrophy

It has been proposed that we should focus our attention on prevention of cardiovascular complication rather than to prevent osteitis fibrosa as the purpose to control secondary hyperparathyroidism (2HPT) induced by chronic renal failure. Active vitamin D and these analogues influence the bone turnover in hemodialysis patients and recently we often encounter the patients whose bone turnover is not high in spite of high PTH level. The aim of parathyroidectomy is gradually changed from improvement of bone disease to reduce high PTH level to prevent cardiovascular complication and extraskeletal symptoms. When it is difficult to control high PTH level without increase of calcium phosphate product, parathyroidectomy should be chosen.     

Parathyroidectomy for advanced renal hyperparathyroidim in hemodialysis

Treatment of advanced secondary hyperparathyroidism should be shifted from to avoid progression of bone disease to protection of cardiovascular complications induced by ectopic calcification. Patients who suffer from advanced secondary hyperparathyroidism with uncontrollable hypercalcemia or/and hyperphosphatemia by medical treatment should be referred to surgical treatment at relatively early time. Total parathyroidectomy with forearm autograft is adequate operative procedure especially in patients who require long-term hemodialysis.